ADU rules in Florissant, MO — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
Missouri has no statewide ADU mandate. Florissant's Zoning Code (Chapter 405) does not authorize accessory dwelling units in single-family R-1 through R-4 districts. Section 405.085 limits R-1 to single-family dwellings plus customary accessory buildings. A duplex requires R-5 zoning.
Florissant's Zoning Code (Title IV, Chapter 405) operates under RSMo Chapter 89. Article IV establishes R-1 through R-4 as single-family districts, R-5 as duplex, R-6 as multiple-family. Section 405.085 limits R-1 to single-family dwellings, churches, schools, and accessory buildings customarily incident to those uses. A duplex is permitted only in R-5 or higher. A detached accessory garage in R-1 is capped at 6% of lot area. Accessory buildings may not exceed 18 feet, the principal building height, or 30% of the required rear yard, and need a 3-foot setback up to 13 feet. The code does not list separate dwelling units as accessory uses, so a second dwelling on a single-family lot requires rezoning.
Constructing a separate dwelling unit on a single-family-zoned lot without rezoning violates Florissant's Zoning Code. Building without a permit violates the adopted residential code. Code enforcement may issue stop-work orders, citations, and fines, or require removal.
Florissant, MO
Florissant City Code §210.750 prohibits loud, unnecessary, or unusual noise that disturbs neighborhood peace. Operating radios, TVs, or music devices between...
Florissant, MO
Florissant Code §205.065 prohibits keeping animals that cause loud noises. Dogs creating persistent barking noise that disturbs neighbors may be cited under ...
Florissant, MO
Florissant regulates amplified music under the general noise ordinance. Sound amplification permits available for events. MO Rev. Stat. §574.010 applies.
Florissant, MO
Florissant's general noise ordinance (§210.750) sets a de facto start time of 7:00 a.m. for activities that could disturb neighbors. No separate specific con...
Florissant, MO
Abandoned vehicles in Florissant are regulated by city ordinances and RSMo §304.157 (48-hour rule on private property). Inoperable vehicles stored on private...
Florissant, MO
Florissant street parking is regulated under city traffic ordinances and state law (RSMo Chapter 300). Standard state prohibitions apply. Posted time limits ...
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